The present invention relates to a communication device and a communication method, and more particularly, to a communication device and a communication method in which a layer 2 network is overlaid on a layer 3 network.
In recent years, demands for infrastructure for accommodating a plurality of tenants (user organizations and their systems) on a large scale and efficiently in data centers and the like have been increasing due to consolidation and integration of servers by network virtualization, cloud computing, and the like. One method of providing infrastructure for accommodating the plurality of tenants on a large scale and efficiently is an overlay method for constructing a logical layer 2 network on an existing layer 3 network. The overlay method performs tunnel communication between virtual switches to encapsulate a layer 2 Ethernet (registered trademark) frame in a layer 3 IP packet. Such an overlay method includes VXLAN (Virtual Extensible VLAN), GRE (Generic Routing Encapsulation), and the like.
WO2014/050091 (JP2015-533045A) discloses a technique of a communication system for distinguishing and managing a network for each user such as an enterprise, a group or the like by a virtual network such as an overlay. When using a virtual network such as an overlay, performance bottleneck can be improved by adjusting the number of packets to be encapsulated by adjusting an MTU (Maximum Transmission Unit) of the packet. However, every time the computing unit is connected to a VPN (Virtual Private Network), the network connection device inquires a network control device about the MTU corresponding to the VPN. Therefore, the bottleneck caused by the MTU inquiry becomes an issue.
It is an object of WO2014/050091 (JP2015-533045A) to reduce the performance bottleneck, and techniques have been disclosed in which, in a communication system including a computing unit that transmits communication data with a plurality of packets and a communication unit that performs packet processing for transmitting the packets via a virtual network, the computing unit adjusts a size of a transmission packet with a packet size selected from a plurality of packet size candidates based on information regarding a forwarding path of the transmission packet transmitted to the communication unit.